O/R

A woman crushes a stick of black chalk with a pestle and mortar, pinches the ground dust into a pile on the floor, leans down, inhales, exhales and blows the dust across the floor. The process is repeated through a grading spectrum of black to white. A second woman kneels beside her and writes on the floor in matching tones a record of the action taking place. They work in synch and in rhythm: one creates a physical action that the other interprets in words. Once the charcoal set is crushed to exhaustion the woman with the now blackened face sits up. Her documenter follows. The documentation of ‘O / R’ is as live as the performance itself. Each mode informs the other and benefits from the particular requirement imposed by a ‘site’. The site here is not just the physical location, but includes the artist's body, the anticipated audience, the environment, and the atmosphere. Rather than prioritising one form over another, each manifestation is seen as having generative potential for further creative responses. This reflexivity relies on the observation of each other’s movements and decisions throughout, and it is this construct that allows the problem of documentation to be analyzed. With no time to reflect, to square up a shot or rephrase a sentence after the event, the integral nature of the work’s document is exposed to complication and chance; it becomes as influential as the action it is intended to record. The ‘live’ context the work represents becomes threefold when exhibited by networked stream: through action, observation and record, and the mediation of these acts across digital terrain. 'O / R' is a five-minute adaption of 'Oral / Response’ produced as a new work exclusively for Low Lives 4 and performed and streamed 27th April 2012

SAGA SERVICE DISCOVERY US E R S GU I D E F O R C+ + P R O G R A M M E R S

The SAGA Service Discovery API provides a way to find grid services matching particular filter

SAGA INFORMATION SYSTEM NAVIGATOR US E R S GU I D E F O R C+ + P R O G R A M M E R S

The SAGA Service Discovery API provides a way to find grid services matching particular filter

Computations on Nondeterministic Cellular Automata

The work is concerned with the trade-offs between the dimension and the time and space complexity of computations on nondeterministic cellular automata. It is proved, that 1). Every NCA \Cal A of dimension $r$, computing a predicate $P$ with time complexity T(n) and space complexity S(n) can be simulated by $r$-dimensional NCA with time and space complexity $O(T^{\frac{1}{r+1}} S^{\frac{r}{r+1}})$ and by $r+1$-dimensional NCA with time and space complexity $O(T^{1/2} +S)$. 2) For any predicate $P$ and integer $r>1$ if \Cal A is a fastest $r$-dimensional NCA computing $P$ with time complexity T(n) and space complexity S(n), then $T= O(S)$. 3). If $T_{r,P}$ is time complexity of a fastest $r$-dimensional NCA computing predicate $P$ then T_{r+1,P} &=O((T_{r,P})^{1-r/(r+1)^2}), T_{r-1,P} &=O((T_{r,P})^{1+2/r}). Similar problems for deterministic CA are discussed.Comment: 18 pages in AmsTex, 3 figures in PostScrip